GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    Caution: Refer to Approved Equipment for Collision Repair Caution in the Preface section.

    Caution: Sectioning should be performed only in the recommended areas. Failure to do so may compromise the structural integrity of the vehicle and cause personal injury if the vehicle is in a collision.

  1. Disable the SIR system. Refer to SIR Disabling and Enabling in SIR.
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.

  3. Object Number: 874301  Size: SH
  4. Remove all of the related panels and the components.
  5. Remove the sealers and anti-corrosion materials from the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair in Paint and Coatings.
  6. Repair as much of the damage as possible. Refer to Dimensions - Body .

  7. Object Number: 876931  Size: SH
  8. Locate the die mark on the outer lower surface of the rear rail, rearward of the #5 bar.

  9. Object Number: 872755  Size: SH

    Important: Do not section the rail in any area other than the die mark location given.

  10. Align a sliding square or similar tool to the line at the tip of the arrow in the die mark. Scribe a line across the rail.

  11. Object Number: 872758  Size: SH
  12. Use the same tool to transfer this scribed line onto the sides and the weld flanges of the rail.

  13. Object Number: 872761  Size: SH
  14. Cut at the marked location.

  15. Object Number: 872770  Size: SH
  16. Remove the damaged component from the vehicle.

  17. Object Number: 882100  Size: SH
  18. Drill 2 8 mm (5/16 in) plug weld holes on each of the 3 sides of the rear rail. Position the center of the holes 10 mm (3/8 in) from the cut edge.

Installation Procedure


    Object Number: 876931  Size: SH
  1. Locate the die marks on the service part rear rail.

  2. Object Number: 872758  Size: SH
  3. Align a sliding square or similar tool to the line at the tip of the arrow in the die mark and scribe a line across the rail.
  4. Use the same tool to transfer this scribed line onto the sides and the weld flanges of the rail.
  5. Place a mark forward, towards the rear of the arrow, 25 mm (1 in) from the scribed line on all 3 sides of the service rail.
  6. Use the tool to scribe a line on all 3 sides and weld flanges of the rail.
  7. Cut at the scribe line at the rear of the arrow.

  8. Object Number: 872770  Size: SH
  9. Remove the rear portion of the rail.

  10. Object Number: 872763  Size: SH
  11. Cut the upper outer flanges of the rear portion of the rear rail service part. Cut the flanges back to the first scribe line and remove the tabs.
  12. Cut the lower radius corners of the service part back to the first scribe line and remove the small corners.
  13. Bend the bottom side of the service part at the sectioning location inward slightly by aligning a vice grip flanging tool or similar tool at the first scribed line.
  14. Prepare the sectioning area of the rear rail for welding.
  15. Apply 3M® Weld-Thru coating P/N 05916 or equivalent to all mating surfaces.

  16. Object Number: 872770  Size: SH
  17. Position the rear rail section using 3-dimensional measuring equipment. Clamp the rail section in place.

  18. Object Number: 876961  Size: SH
  19. Tack weld the part into position.
  20. Inspect the service rear rail for proper dimensions, using 3-dimensional measuring equipment.
  21. Plug weld at each 8 mm plug weld hole location.
  22. Stitch weld along the entire sectioning joint. Make welds along the seam with 25 mm (1 in) gaps between. Weld the gaps.
  23. Clean and prepare the welded surfaces.
  24. Install all of the related panels and components.
  25. Apply the sealers and anti-corrosion materials to the repair area, as necessary. Refer to Anti-Corrosion Treatment and Repair in Paint and Coatings.
  26. Paint the repaired area. Refer to Anti-Corrosion Treatment and Repair in Paint and Coatings.
  27. Enable the SIR system. Refer to SIR Disabling and Enabling in SIR.
  28. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.